Landslide Inventory and Susceptibility Mapping for a Proposed Pipeline Route, Yukon Alaska Highway Corridor, Canada

摘要

In Canada’s north, slope stability is a critical issue affecting infrastructure. There are several types of landslides and ground hazard features that are directly related to the presence of permafrost: active layer detachment slides, retrogressive thaw flows, solifluction, thermo-karstic depressions, and rock glaciers. A landslide inventory and preliminary susceptibility assessment of debris flows and rockfalls/rock slides were carried out for a proposed pipeline route along the Yukon Alaska Highway Corridor (YAHC). The YAHC covers a linear distance of 950 km with a 40 km width. A total of 2,018 geohazard features including 1743 landslides were identified, which represents about 1 landslide per 17 km~2. Prominent landslide types included debris slides (31 %), debris flows and fans (28 %), rock slides (11 %), solifluction (8 %), earth slides/flows (5 %), thermo-karstic depressions (5 %), rockfalls (4 %), and combined retrogressive thaw flows and active layer detachments (1 %). Rock glaciers were also identified (6 %). The qualitative heuristic debris flow susceptibility map indicates that 73 % of the debris flow deposits occur downstream from a high susceptibility zone and 23%downstream from the moderate susceptibility zone. For the qualitative heuristic rockfall/rock slide susceptibility map, 76 % of the known failures occur in the high susceptibility zone and 17 % in the moderate susceptibility zone. Thus, as preliminary qualitative landslide susceptibility mapping, this is considered a good correlation between the maps and landslide inventory.